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dc.contributor.advisorWu, Ying
dc.contributor.authorXiao, Bingmu
dc.date.accessioned2013-06-19T08:36:43Z
dc.date.available2014-05-30T00:00:00Z
dc.date.issued2013-05
dc.identifier.doi10.25781/KAUST-7P7R5
dc.identifier.urihttp://hdl.handle.net/10754/294181
dc.description.abstractIn this thesis, wave propagation through acoustic materials with subwavelength slits structures is studied. Guided by the findings, acoustic wave focusing is achieved with a specific material design. By using a parameter retrieving method, an effective medium theory for a slab with periodic subwavelength cut-through slits is successfully derived. The theory is based on eigenfunction solutions to the acoustic wave equation. Numerical simulations are implemented by the finite-difference time-domain (FDTD) method for the two-dimensional acoustic wave equation. The theory provides the effective impedance and refractive index functions for the equivalent medium, which can reproduce the transmission and reflection spectral responses of the original structure. I analytically and numerically investigate both the validity and limitations of the theory, and the influences of material and geometry on the effective spectral responses are studied. Results show that large contrasts in impedance and density are conditions that validate the effective medium theory, and this approximation displays a better accuracy for a thick slab with narrow slits in it. Based on the effective medium theory developed, a design of a at slab with a snake shaped" subwavelength structure is proposed as a means of achieving acoustic focusing. The property of focusing is demonstrated by FDTD simulations. Good agreement is observed between the proposed structure and the equivalent lens pre- dicted by the theory, which leads to robust broadband focusing by a thin at slab.
dc.language.isoen
dc.subjectAcoustic Focusing
dc.subjectEffective Medium Theory
dc.subjectSub wave length
dc.titleFocusing of Acoustic Waves through Acoustic Materials with Subwavelength Structures
dc.typeThesis
dc.contributor.departmentPhysical Science and Engineering (PSE) Division
dc.rights.embargodate2014-05-30
thesis.degree.grantorKing Abdullah University of Science and Technology
dc.contributor.committeememberKeyes, David E.
dc.contributor.committeememberSchuster, Gerard T.
thesis.degree.disciplineEarth Science and Engineering
thesis.degree.nameMaster of Science
dc.rights.accessrightsAt the time of archiving, the student author of this thesis opted to temporarily restrict access to it. The full text of this thesis became available to the public after the expiration of the embargo on 2014-05-30.
refterms.dateFOA2014-05-30T00:00:00Z


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